Rapid Assessment Reference Condition Model
The Rapid Assessment is a component of the LANDFIRE project. Reference condition models for the Rapid Assessment were
created through a series of expert workshops and a peer-review process in 2004 and 2005. For more information, please visit
www.landfire.gov. Please direct questions to helpdesk@landfire.gov.
R3SPFI
Potential Natural Vegetation Group (PNVG)
Spruce - Fir
General Information
Contributors (additional contributors may be listed under "Model Evolution and Comments")
Modelers
Reviewers
Jim Griffin
Vegetation Type
Forested
Dominant Species*
PIEN
ABLA
PICO
POTR
jgriffin01@fs.fed.us
William L. Baker
General Model Sources
Literature
Local Data
Expert Estimate
LANDFIRE Mapping Zones
14
24
28
15
25
23
27
bakerwl@uwyo.edu
Rapid AssessmentModel Zones
California
Great Basin
Great Lakes
Northeast
Northern Plains
N-Cent.Rockies
Pacific Northwest
South Central
Southeast
S. Appalachians
Southwest
Geographic Range
Colorado, northern New Mexico and parts of Arizona and Utah. Elevations typically range from 950011,000 feet.
Biophysical Site Description
PNVG occurs in the subalpine zone on gentle to moderately steep terrain (e.g., 10-60% slope).
Vegetation Description
The overstory is typically dominated by Engelmann spruce and/or subalpine fir.. Other tree species may
include lodgepole pine, aspen, limber pine, bristlecone pine, and Douglas-fir. Cork bark fir occurs in the
southern part of the zone. Lodgepole pine does not occur in this PNVG south of 38 degrees 30 minutes
(approximate). Common understory species include Vaccinium myrtillus, Polemonium pulchemimum,
Ligularia, and Erigeron eximus.
Disturbance Description
Fire Regimes V and IV: Primarily long-interval (e.g., 150-300 yr) stand replacement fires, with very minor
amount of terrain influenced by mixed severity fires. Disturbances also include insect/disease and
windthrow events.
Adjacency or Identification Concerns
This PNVG may be similar to the PNVGs R0SPFI from the Northern and Central Rockies model zone and
R2SPFI from the Great Basin model zone.
Local Data
Expert Estimate
Literature
Sources of Scale Data
Scale Description
Patch sizes vary but are mostly in the hundreds of acres, with occasional very large patches (disturbances) in
the thousands of acres. There may be frequent small disturbances in the 10s of acres or less.
Issues/Problems
*Dominant Species are from the NRCS PLANTS database. To check a species
code, please visit http://plants.usda.gov.
Final Document 9-30-2005
Page 1 of 4
Model Evolution and Comments
This model is based on the original FRCC model SPFI 5 with quantitative changes made in distribution of
vegetation classes and description of vegetation.
Peer review suggested aligning this PNVG with similar types from other modeling zones. As a result, this
type was remodeled and more closely reflects models for high elevation spruce-fir in other zones.
Succession Classes**
Succession classes are the equivalent of "Vegetation Fuel Classes" as defined in the Interagency FRCC Guidebook (www.frcc.gov).
Class A
5%
Early1 PostRep
Description
Early succession after moderately
long- to long interval replacement
fires
Dominant Species* and
Canopy Position
PIEN
ABLA
15 %
Mid1 Closed
Description
Shade tolerant- and mixed conifer
saplings to poles (>60% canopy
cover)
Cover
Height
Tree Size Class
Upper Layer Lifeform
Herbaceous
Shrub
Tree
Fuel Model
Class B
Mid1 Open
Description
Primarily moderately tolerant
saplings to poles (1" - 6.9" dbh)
and <50% canopy cover
Max
100 %
no data
no data
no data
Upper layer lifeform differs from dominant lifeform.
Height and cover of dominant lifeform are:
Dominant Species* and
Canopy Position
Structure Data (for upper layer lifeform)
PIEN
ABLA
Cover
Height
Tree Size Class
Upper Layer Lifeform
Fuel Model
20 %
Min
0%
no data
Herbaceous
Shrub
Tree
Class C
Structure Data (for upper layer lifeform)
Min
50 %
Max
100 %
no data
no data
no data
Upper layer lifeform differs from dominant lifeform.
Height and cover of dominant lifeform are:
no data
Dominant Species* and
Canopy Position
Structure Data (for upper layer lifeform)
PIEN
ABLA
Cover
Height
Tree Size Class
Upper Layer Lifeform
Herbaceous
Shrub
Tree
Fuel Model
Min
0%
no data
Max
50 %
no data
no data
Upper layer lifeform differs from dominant lifeform.
Height and cover of dominant lifeform are:
no data
*Dominant Species are from the NRCS PLANTS database. To check a species
code, please visit http://plants.usda.gov.
Final Document 9-30-2005
Page 2 of 4
Class D
20 %
Late1 Open
Description
Poles (5" dbh+)- and larger
diameter moderately shade tolerant
conifer species (<50% canopy
cover) in small- to moderate size
patches, generally on south aspects
Dominant Species* and
Canopy Position
Structure Data (for upper layer lifeform)
PIEN
ABLA
Cover
Height
Upper Layer Lifeform
Herbaceous
Shrub
Tree
40 %
Late1 Closed
Description
Pole- and larger diameter
moderately to shade tolerant
conifer species (>50% canopy
cover), in moderate to large size
patches, all aspects
Max
50 %
no data
Tree Size Class
Fuel Model
Class E
Min
0%
no data
no data
Upper layer lifeform differs from dominant lifeform.
Height and cover of dominant lifeform are:
no data
Dominant Species* and
Canopy Position
Structure Data (for upper layer lifeform)
PIEN
ABLA
Cover
Min
50 %
Height
no data
Tree Size Class
Upper Layer Lifeform
no data
no data
Upper layer lifeform differs from dominant lifeform.
Height and cover of dominant lifeform are:
Herbaceous
Shrub
Tree
Fuel Model
Max
100 %
no data
Disturbances
Disturbances Modeled
Fire
Insects/Disease
Wind/Weather/Stress
Native Grazing
Competition
Other:
Other
Historical Fire Size (acres)
Avg: no data
Min: no data
Max: no data
Sources of Fire Regime Data
Literature
Local Data
Expert Estimate
Fire Regime Group: 5
I: 0-35 year frequency, low and mixed severity
II: 0-35 year frequency, replacement severity
III: 35-200 year frequency, low and mixed severity
IV: 35-200 year frequency, replacement severity
V: 200+ year frequency, replacement severity
Fire Intervals (FI)
Fire interval is expressed in years for each fire severity class and for all types of
fire combined (All Fires). Average FI is central tendency modeled. Minimum and
maximum show the relative range of fire intervals, if known. Probability is the
inverse of fire interval in years and is used in reference condition modeling.
Percent of all fires is the percent of all fires in that severity class. All values are
estimates and not precise.
Replacement
Mixed
Surface
All Fires
Avg FI
Min FI
Max FI
Probability
210
5000
150
35
300
100
0.00476
0.0002
201
Percent of All Fires
96
4
0.00497
References
Alexander, R.R. and O. Engelby. 1983. Engelmann spruce - subalpine fir. In: Silvicultural systems for the
major forest types of the United States. Agriculture Handbook 445. Washington, D.C, U.S. Dept. of
Agriculture.
Buechling, A., and W. L. Baker. 2004. A fire history from tree rings in a high-elevation forest of Rocky
*Dominant Species are from the NRCS PLANTS database. To check a species
code, please visit http://plants.usda.gov.
Final Document 9-30-2005
Page 3 of 4
Mountain National Park. Canadian
Journal of Forest Research 34:1259-1273.
DeVelice, Robert L. et al. 1986. A Classification of Forest Habitat Types of Northern New Mexico and
Southern Colorado. USDA, Forest Service. Rocky Mountain Forest and Range Experiment Station. GTR
RM-131.
Komarkova, Vera et al. 1988. Forest Vegetation of the Gunnison and Parts of the Uncompahgre National
Forests: A Preliminary Habitat Type Classification. USDA Forest Service, Rocky Mountain Forest and
Range Experiment Station. GTR RM-163.
Sibold, J. 2001. The forest fire regime of an upper montane and subalpine forest, Wild Basin, Rocky
Mountain National Park. M.S. Thesis, University of Colorado, Boulder, CO.
Veblen, T. T., K. S. Hadley and M. S. Reid. 1991. Disturbance and stand development of a Colorado
subalpine forest. Journal of Biogeography (1991) 18:707-716.
Veblen, T. T., K. S. Hadley, E. M. Nel, T. Kitzberger, M. S. Reid, and R. Villalba. 1994. Disturbance
regime and disturbance interactions in a Rocky Mountain subalpine forest. Journal of Ecology 82:125-135.
*Dominant Species are from the NRCS PLANTS database. To check a species
code, please visit http://plants.usda.gov.
Final Document 9-30-2005
Page 4 of 4